The targeting vector is designed to insert, by site-directed mutagenesis, a T(CG) to A(CG) point mutation followed by a FRT-flanked neomycin cassette 290 bp downstream of exon 1. The mutation results in an alteration of the corresponding amino acid from serine to threonine (S32T) at codon 32. The mutation does not affect phospholipase A2 activity, but does result in impaired trafficking of PRDX6 to the into lamellar bodies and lysosomes of the lung epithelium.